1. Field of the Invention
The present invention relates to an electronic scope arranged in such a manner that a frame body, to which a solid state imaging device is fastened, is detachably inserted into an inserting section so that the solid state imaging device can be easily interchanged.
2. Description of the Related Art
Recently, an electronic scope has been widely used which is capable of forming an image of a portion of the body cavity of a patient to be observed by using imaging means which employs a solid state imaging device such as a charge coupled device (CCD) by inserting an elongated portion of the electronic scope into a portion of the body cavity to be observed (to be called a "observation portion" hereinafter).
An electronic scope of the type described above has an advantage in that an excellent resolution can be obtained in comparison to the fiber scope and another advantage in that image processing such as an enlargement of an image and a comparison of two images can be easily performed. There are two types of methods of forming a color image in the above-described electronic scope, that is, a plane successive method in which illuminating light is successively switched to red, green and blue and a color mosaic method (also called a "simultaneous method") in which color filters through which respective color light beams red, green and blue can pass through are placed in front of the solid state imaging device, the color filters being placed in a mosaic manner. The plane successive method has an advantage with respect to the color mosaic method in that the number of pixels can be reduced, while the color mosaic method has an advantage in that an off color can be prevented.
As disclosed in Japanese Patent Laid-Open No. 63-259613 and Japanese Patent Laid-Open 63-286125, the above-described solid state imaging device has been adhered to an inner tube which constitutes the inserting section.
According to the above-described conventional structures, the solid state imaging device, which can be most easily broken, is secured to the forward elements or the inner tube which constitutes the inserting section. Therefore, if the solid state imaging device is desired to be interchanged for the purpose of subjecting it to a repairing operation or the like, the above-described elements which constitute the inserting section must be respectively disassembled.
However, the above-described elements constituting the inserting section are strongly secured and hermetically sealed up for the purpose of preventing their separation when the inserting section is inserted into the body cavity and maintaining the water tightness. Therefore, the elements constituting the inserting section cannot be easily assembled/disassembled. As a result, a too long time undesirably takes to complete the assembling/disassembling work, causing a trouble in the inspection and curing schedule in the hospital. Furthermore, the disassembled elements may not be completely assembled again, causing the separation of the elements or water leakage to occur. As described above, it has been difficult to maintain the quality of the electronic scope after it has been subjected to the repairing operation.